Nonsmudging duplicating ink



Patented July 28, 1953 N ON SMUDGING DUPLICATIN G INK William N. B.Armstrong and Hyman S. Kredentser, Toronto, Ontario, Canada, assignorsto Ontario Research Foundation, Toronto, Ontario,

Canada No Drawing. Application February 13, 1950, Serial No. 144,036

3 Claims. (Cl. 106--26) This invention relates to transfer orduplicating inks, and more particularly to a new and useful transfer orduplicating ink which can be applied in the same manner as ordinaryprinting inks on standard types of printing presses or the like.

In many different types of business forms it is desirable that thesheets contain on the reverse side throughout at least certain areas atransfer or carbon material as is well known in the manifolding art sothat writing occurring in these areas is duplicated on an undersheet.

It is highly desirable that such business forms be spot carbonized aseconomically as possible and therefore desirable that the application ofthe transfer or carbon material be capable of being made by a printingpress or the like.

To such end it has heretofore been proposed to apply the transfermaterial as a grease type ink such as a grease carbon ink. Such an inkwhile lending itself to a printing press contains ingredients such aslinseed oil which causes premature or rapid hardening with a resultingloss of transfer properties on aging. Further this type of ink also hasthe disagreeable property of smudging.

It ha also been proposed to apply the transfer material as a hot-meltwax-carbon ink. Such an ink does essentially eliminate smudging andmaintains its transfer properties on aging. However, a certain amount ofundesirable penetration is experienced when coating paper with this ink.Another disadvantage which is a serious one is that the ink must have ahot application requiring special equipment, heat, and a skilledoperator to maintain the necessary controls of application.

As an improvement over the hot melt waxcarbon ink it has also beenproposed to convey the transfer or carbon material to the paper in acold application by means of a suitable volatile vehicle in whichtransfer and wax particles are suspended or dispersed but which does notdissolve the wax in an unheated state. However, to complete theformation of the transfer surface the printed area must be subsequentlyheat treated to cause the wax and/or the like to fuse and to drive offthe unwanted volatile.

It is therefore the object of this invention to overcome thedisadvantage of such previous proposals by providing a transfer orduplicating ink composition which can be applied in a cold applicationin the same manner as ordinary printing inks on standard types ofprinting presses without penetration of the paper to provide a 2resultant film which will be non-smudging, have an excellent transferproperty and will maintain its original transfer property afterlong-time aging.

This object is obtained by providing a novel transfer or duplicating inkcomposition in which the duplicating or transfer film formingconstituents are carried to the paper by a nonpenetrating quick dryingsolvent and are capable of drying almost instantaneously into anonsmudging, flexible transfer film with excellent transfer properties.

More specifically the principal feature of the invention resides in theprovision of a transfer ink composition comprising a wax-oil-colourblend, a hardening agent in the form of a friable resin, a primary amideof a long chain fatty acid forming a thickening agent, a film formingagent, and a filler, dispersed in an organic solvent. A combination ofthe above ingredients can produce a transfer film which will be ofsuflicient hardness and flexibility, be non-smudging yet can be brokenby the pressure of a pencil and will provide excellent transferproperties undiminished on aging. By a suitable choice of film formingingredients and solvent the paper will not be penetrated and thedistillation range can be chosen as such as to meet the particularapplication of the ink, for instance, application by doctor blade orapplication by a standard printing press so that the composition willhave the requisite rate of drying, that is, the solvent will have-therequisite rate of evaporation suitable for the method of application.

In most applications the ink composition desired is a carbon ink but itwill be understood that the invention is applicable to and includes anytransfer or duplicating ink affording cold solvent application inaccordance with the teachings herein disclosed.

For a non-smudging carbon ink for duplicating-paper compounded inaccordance with this invention a suitable wax-oil-colour blend comprisesa blend of waxes, a paraffin oil, pigments, dyes and a wetting agent forthe pigments and a solvent for the dyes. Such a wax-oilcolour blend iscommon in the industry and this invention makes no claim to novelty ofsuch a blend. An example of a suitable wax-oil-colour blend is a mixtureof ouricury wax, paraffin wax (133-136 F. M. P.) Bareco F. M. P.)Peerless Black, Static Black, ink oil, methyl violet, and oleic' acid.

The functioning of each of the above ingredients is well understood inthe art and further 3 particulars as to their functioning or toequivalent substitutes are not deemed necessary to the understandin ofthis invention.

First attempts at carrying such a wax-oil-colour blend to the paper by acold solvent application included milling the mixture hot and dissolvingit after milling in a solvent and adding a resin to harden the film andpreventing smudging upon evaporization of the solvent or drying of thefilm. Such a composition however gave unsatisfactory results indicatingthat the highly desirable cold application of a transfer or duplicatingink was not feasible.

We have discovered however that if with the wax-oil-colour blend, andresin, a primary amide of a long chain fatty acid, a film forming agentof the nature of ethyl cellulose, and an inert pigment filler arecombined they can be dissolved or dispersed in an active solvent or ablend of active solvent and a diluent of a suitable distillation rangefor the desired method of application and carried to the paper by coldapplication to have the same consistency and drying qualities asordinary printing ink for application by a printing press, doctor bladeor the like and providing upon drying a more desirable transfer filmthan has heretofore been possible. The film that is obtained accordingto our discovery is sufiiciently hard and flexible to prevent smudgingand cracking respectively and yet can readily be broken by the pressureof the pencil to provide an excellent transfer property which remainsundiminished on long aging.

According to our invention a specific example of a non-smudging carbonink for duplicating paper which retains its initial transfer propertieson aging consists of:

Example I Parts by Weight Wax-oil-colour blend 126 Bentonite filler 30Glycerol ester of hydrogenated rosin 26 A blend of primary amides oflong-chain fatty acids 1 Ethyl cellulose N200 1.3

Aromatic petroleum solvent having a distillation range of 345 F. to 412F 17-2 A. suitable amide blend consists of 25% hexadecanamide; 70%octadecanamide; and o'ctadecen'aml'de.

The wax-oil-colour blend is milled with the bentonite in the aboveexample and consists of:

Parts by weight Ouricury wax 27 Parafiin wax (125 F. to 128* F.) 21Microcrystalline wax (165 F.) 5.25 High strength carbon black 27 Mediumstrength carbon black Ink oil (a light parafiin oil) 22.50 Methyl violetdye 0.75 Nigrosine dye "6. Oleic acid 1.50

4 becomes dry by evaporation of the solvent. In addition to the aboveidentified glycerol ester of hydrogenated rosin other resins of thisclass include hydrogenated rosin, polymerized resin, chlorinateddiphenyls, and arylsulfonamide formaldehyde resins.

The amount of friable resins must be controlled to prevent the filmformed on spot carbonizing with the transfer ink composition compoundedin accordance with this invention from losing its property to transfer.

We have found that by including a film forming material as a reinforcingstructure for the non-film forming materials we are able to produce thedesired viscosity of the composition for cold solvent application in aprinting press or the like and by virtue of its film forming propertiesthe inclusion of such an agent has been found to contribute to thenon-smudging characteristic of the dried film. A suitable film formingagent of this kind is ethyl cellulose, or chlorinated rubber, or vinylresins.

In Example I above the ethyl cellulose N-ZOD serves in the capacity of afilm forming agent. The proportion of the film-forming agent must bekept low in order to retain the transfer properties of the dried inkfilm.

An important feature of the inclusion of the amide is that not only doesit permit with the other constituents the formation of a nonsmudgingfilm with highly desirable transfer properties which are retained onlong-aging but it has been found to enhance the colour of the ink whilenot in itself being a coloured compound.

The primary amide of a long-chain fatty acid according to this inventionis a primary amide of a fatty acid containing from 6 to '20 carbon atomsin the molecule. Commercially these amides are usually blends of amidesof closely related chemical properties. An example of a suitable amideblend consists as described above of 25 hexadecanamide; octadecanamide;and 5% octadecenamide.

According to this invention the solvent is preferably non-polar tominimize penetration of the paper. The choice of solvent will dependpartly on the method of application of the ink to the paper, e. g.doctor blade, the type of paper and composition of the ink. The solventrequired must not evaporate too fast yet must afford an ink of aconsistency of the order of the grease carbon inks being used at thepresent time.

We have found that an excellent solvent is an aromatic hydrocarbonhaving a distillation range between 345 F. and 412 F. This solventpermits of cold solvent application with excellent results with thepresence of a filler such as the bentonite clay of the above example.

All solvents having the desired solvent power for dissolving thewax-oil-colour blend, resin, amides, and film former cannot be'successfully used as with some their evaporation rate is too high.

By providing a solvent of the type of an aromatic hydrocarbon thesolvent power is increased but the evaporation rate is excellent for thecold solvent application. We have found however that it is possible touse these higher power solvents without disturbing the desiredconsistency of the ink and without in any way destroying the transfercharacteristics of the resulting film by incorporating .a .filler suchas the bentonite clay in the ink composition.

Other solvents which permit this invention to be carried out arechlorinated hydrocarbons, aromatics, parafilns and terpenes.

It will be noted that the inclusion of a filler permits of the use of asolvent affording the nee-es sary characteristics for satisfactory coldsolvent application while at the same time maintains in the dried filmthe desired characteristics of nonsmudge and excellent transferproperties initially and on long-time aging. While bentonite clay hasbeen named and bentonite clay of 625 mesh has been found particularlydesirable, it will be understood that other clays and for instancewhiting can also be successfully employed.

Each of the above ingredients, the wax-oilcolour blend; the filler suchas bentonite clay; the friable resin such as glycerol ester ofhydrogenated rosin; the primary amide of a long chain fatty acid; andthe film former such as ethyl cellulose; carried to the paper in a coldsolvent application dissolved or dispersed in a solvent of the nature ofan aromatic hydrocarbon, plays an important interrelated role indetermining the form of the dried film to provide a cold applicationfilm having the characteristics of a non-smudging transfer film whichretains its initial transfer properties on aging.

The additives to the wax-oil-colour blend in their proper proportionscontribute one or more property to the finished product and severalofthe additives appear to influence the same property with the result thatall the additives unite to form a mixture or blend giving the desiredfinal properties of the cold application ink which have long been soughtfor in the art.

A further example of a duplicating ink in accordance with this inventionis given as Example II below:

Aromatic petroleum solvent having a distillation range of 345 F. to 412F 172 This above formulation of Example II gives the wax-oil colourblend as admixed with bentonite which mixture may be referred to as awax-bentonite mixture in accordance with Example 11 comprises the samemixture as the Wax-oil-colour blend and bentonite mixture of Example Iabove.

To afford a smooth film the bentonite clay is preferably hot milled withthe wax-oil-colour blend providing at the same time increased dispersionand grinding of the carbon improving the transfer property of the ink asWell as increasing the film smoothness.

The amount of film former such as ethyl cellulose must be retainedfairly low to maintain the transfer property of the ink and contrary towhat might appear to be the case the film former cannot be relied uponto provide the desired viscosity for printing consistency because of itslimitation on the transfer characteristic of the film.

In addition to Examples I and II above other formulae providing thehighly desirable nonsmudging duplicating ink in accordance with thisinvention are set forth below, Examples III, IV and V being examples offormulae suitable for use on standard types of printing presses, and EX-ample VI being a formulation suitable for application by means of adoctor blade or scraper blade.

6 Example III Parts by weight Wax-oil-colour blend 126 Bentonite filler30 Chlorinated diphenyl resin (softening point: C.-105.5 C.) 26 A blendof primary amides of long-chain fatty acids 26 Ethyl cellulose, N-2001.3

Aromatic petroleum solvent having a'distillation range of 345 F.-412 F172 In this example it will be seen that the resin used is chlorinateddiphenyl resin.

Example IV Parts by weight Wax-oil-colour blend 126 Bentonite filler 30Chlorinated diphenyl resin (softening point 100-105C.) 26 A blend ofprimary amides of long-chain fatty acids 26 Chlorinated rubber cps.)1.3,

Aromatic petroleum solvent having a distillation range of 345 F.4l2 F.172

Again it will be seen that the resin used is chlorinated diphenyl resin.The film former used in this formulation is chlorinated rubber.

Example V Parts by weight Wax-oil-colour blend 126 Bentonite filler 30Aryl sulphonamide-formaldehyde resin 26 A blend of primary amides oflong-chain fatty acids 26 Polyvinyl acetate resin. (60 cps.) 2.6

Aromatic petroleum solvent having a distillation range of 345 F. to 412F 172 This formula shows the use of still a. different resin as well asanother film forming agent.

It is to be understood that these formulations which are suitable forstandard printing press application, are by way of specific examples andnot by Way of limitation.

Emample VI ("Suitable for doctor blade or scraper blade application)Parts by weight Wax-oil-colour blend 126 Bentonite filler 30 Glycerolester of hydrogenated rosin 78.2 A blend of primary amides of long-chainfatty acids 57.7 Ethylcellulose, N-200 5.2

Aromatic petroleum solvent having a distillation range of 273 F. to 365F 660 In this latter example it will be seen that the quantities ofresin, amide blend and film forming agent have been increased relativethe amount of wax-oil-colour blend and pigment filler, and the amount ofsolvent has also been materially increased. It will thus be seen thatthe proportions of ingredients are dependent on the application method,but the novel combination of ingredients is maintained to permit coldsolvent application.

In attaining a duplicating ink composition which can be applied to thepaper in a cold solvent application and the conception of a cold solventduplicating ink application wherein no further processing is requiredafter application a definite advance in the mam-folding andspotcarbonizing art is presented.

It will be understood that the elimination of the hot-melt applicationand its accompanying disadvantages and the elmination of coldapplication requiring further film forming processing, much time, labourand money that has previously been expended is. eliminated providing avital reduction in manufacturing, costs.

Further, by providing a, duplicating ink that can be handled similarlyin a printing press to present. printing inks, the film can be appliedwith the same ease and facility and with the same skill as the printingmaterial by the ordinary printer.

Even in addition to facility of application, the present inventionaffords in the applied film more permanent transfer qualities, betterresistance to abrasion, a smoother, more uniform, and bettertransferring film than has heretofore. been pro.- vided by othermethods.

It will be understood that various changes may be made from the specificexamples. set forth and various substitutes employed within the scope ofthis invention where the. ink is carried to the paper in a cold solventapplication.

In. the foregoing, cold solvent application is intended to cover andinclude those applications wherein the duplicating ink is carried to thepaper at. temperatures at which ordinary printing ink can. betransferred and below that range of temperatures required for thehot-melt process whereinv special heating apparatus is required.

What we claim as our invention is:

1.. A non-smudging carbon ink for duplicating. paper forsolventapplication comprising, the following. ingredients substantiallyin the proportion set forth by weight, 126 parts wax-oil-colour blend,30 parts bentonite filler, 26v parts glycerol ester of hydrogenatedrosin, 26. parts of a blend of primary amides of long-chain fatty acids,2.6

8 parts ethyl, cellulose N-200; and 172 partsare matic petroleum solventhaving a distillation range of 345 F. to 412 F. in which the aboveconstituents are dissolved.

the

2. An ink as claimed in claim 1 in which blend of primary amidesconsists of 25- per cent hexadecanamide, per cent octadecanamide, and 5per cent octadecenemide.

3. A non-smudging duplicating ink for coldapplication. comprising thefollowing ingredients in approximatelythe following proportions byweight: 126' parts of a wax-oil-oolour blend, 30 parts clay filler, 26parts of a compatible friable resin resistant to oxidation andpolymerization,

v 26 parts of a blend of primary amides of longchain fatty acids, 1 to 3parts ethyl cellulose and- 1-72 parts solvent.

WILLIAM N. B. ARMS'I'RONG. HYMAN S. KREDENTSER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,826,696 Charch Oct. 6, 1931 2,082,592 Nollau June 1, 19372,147,180 Ubben Feb. 14, 1939 2,206,636 Hunter July 2, 1940 2,213,644Antrim Sept. 3, 1940 2,275,101 Ellis Mar. 3, 1942 2,236,812 Wiggam Aug.17, 1943 FOREIGN PATENTS Number Country Date 267,625 Great Britain Mar.22, 1927 420,545 Great Britain Nov. 28, 1934 448,578 Great Britain June11, 1936 459,344 Great Britain Jan. 6', 1937 90,199 Sweden Sept. 14,1937

3. A NON-SMUDGING DUPLICATING INK FOR COLD APPLICATION COMPRISING THEFOLLOWING INGREDIENTS IN APPROXIMATELY THE FOLLOWING PROPORTIONS BYWEIGHTD 126 PARTS OF A WAX-OIL-COLOUR BLEND, 30 PARTS CLAY FILLER, 26PRTS OF A COMPATIBLE FRIABLE RESIN RESISTANT TO OXIDATION ANDPOLYMERIZATION, 26 PARTS OF A BLEND OF PRIMARY AMIDS OF LONGCHAIN FATTYACIDS, 1 TO 3 PARTS ETHYL CELLULOSE AND 172 PARTS SOLVENT.